objective-c - Objective C for 循环延迟

Question

我有一个 for 循环，我想在迭代之间添加延迟。我已将 waitUntilDone 更改为 YES 并获得相同的结果。我的数组中只有两个数字，并且都在五秒后被调用，而不是:

0s - 没有 5s - block 叫 10s- block 调用

for(NSNumber* transaction in gainsArray) {

    double delayInSeconds = 5.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void) {

        NSLog(@"Block");

        [self performSelectorOnMainThread:@selector(private_addTransactionToBankroll:)
        withObject:transaction waitUntilDone:NO];

    });
}

2015-06-16 20:11:06.485 TestApp[97027:6251126] Block
2015-06-16 20:11:06.485 TestApp[97027:6251127] Block

如果重要的话，我正在使用 Cocos2d

Answer 1

for 循环将一个接一个地调度，因此它们基本上会延迟相同的时间。
而是为每个设置不同的递增延迟:

double delayInSeconds = 0.0;
for(NSNumber* transaction in gainsArray)
{
    delayInSeconds += 5.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(void)
                   {
                       NSLog(@"Block");
                       [self performSelectorOnMainThread:@selector(private_addTransactionToBankroll:)
                                              withObject:transaction
                                           waitUntilDone:NO];

                });
}